the loose boards (and also the park) have a lot of flex.
that means the rocker-line increases with the pressure. that's rally cool, because more rocker makes the board slower and better controllable in high wind conditions.
when you ride in choppy water, the flex shows some disadvantages - i can also imagine that you can't pop into big airs out that good with a flexing board.
the loose AX boards go upwind automatically when there's enough pressure for flex

if you have any chance to test it before, you should do it. If someone writes a test, you never know exactly how the board would ride with you on top of it and conditions are always different.
Since you are from Germany, wait until the "King of the Coast" where you can test at least the new Loose boards. Or maybe ask your local dealer.

But the a.m. statement from Murdoc is correct.
Good upwind when enough pressure, not as good for jumping (small pop and large jumps)